Plasma-Synthesized Silver Nanoparticles on Electrospun Chitosan Nanofiber Surfaces for Antibacterial Applications.

Chitosan nanofibers have been electrospun with poly(ethylene oxide) and silver nitrate, as a coelectrospinning polymer and silver nanoparticle precursor, respectively. The average diameter of the as-spun chitosan nanofibers with up to 2 wt % silver nitrate loading was approximately 130 nm, and there was no evidence of bead formation or polymer agglomeration. Argon plasma was then applied for surface etching and synthesis of silver nanoparticles via precursor decomposition.

Conducting silver networks based on electrospun poly(methyl methacrylate) and silver trifluoroacetate.

Silver networks with high transmittance and low resistance were prepared on transparent substrates via a polymer-assisted electrospinning technique and post treatments. Nonaqueous media containing poly(methyl methacrylate) (PMMA) and silver trifluoroacetate (STA) were formulated and electrospun as polymer/metal-precursor nanofibers with as-spun fiber diameters ranging from 640 to 3000 nm. Nanofibers randomly deposited on transparent substrates formed a plane scaffold, which served as the raw material for the conducting silver network.

Assembly and manipulation of Fe(3)O(4)/coumarin bifunctionalized submicrometer Janus particles.

Magnetic and fluorescent bifunctionalized Janus particles were fabricated via sequential particle embedding and surface modifications. The two hemispherical surfaces of a 500 nm silica particle were separately functionalized with Fe3O4 nanoparticles and coumarin dye molecules. The Fe3O4 hemisphere exhibited magnetically driven particle orientation and alignment, whereas the coumarin hemisphere served as an anisotropic emission indicator.

Energetic-assisted scanning thermal lithography for patterning silver nanoparticles in polymer films.

Energetic-assisted scanning thermal lithography (SThL) was demonstrated with the addition of benzoyl peroxide (BPO) for patterning silver nanoparticles. SThL samples were prepared by spin-coating poly(methyl methacrylate) (PMMA) thin films preloaded with BPO and silver nitrate precursors. Localized thermal analysis via probe heating demonstrated that the BPO decomposition in the polymer film took place at the temperature of 80 °C.

Fabrication and characterization of asymmetric Janus and ternary particles.

Asymmetric Janus and ternary silica particles with an average diameter of 450 nm were fabricated by sequentially arranged particle-embedding and surface-modification processes. Thermally induced embedding of particles into polymer-fiber substrates allowed for precise control of the degree of particle submergence and the subsequent chemical modification of the hemispherical exposed particle surfaces. In addition to Janus particles with the desired surface-functionality ratios of 1:2, 1:1, and 2:1, this unique fabrication approach was also used to produce complicated and well-defined heterogeneous materials, including bifunctionalized Janus and ternary particles.

Enhancement of light scattering and photoluminescence in electrospun polymer nanofibers.

Poly(methyl methacrylate) nanofibers with desired fiber diameters that ranged from 336 to 896 nm were electrospun as light scattering and propagation materials. The light scattering behavior of these samples as a function of the fiber diameter and fiber deposition thickness was examined by UV-vis spectrophotometry, which revealed the scattering bands in the absorption spectra. The scattering bands of these nanofibers were linearly proportional to the fiber diameter, which shows good agreement with a scattering model based on the Mie theory.

Dependence of surface atomic arrangement of titanium dioxide on metallic nanowire nucleation by thermally assisted photoreduction.

Through studying the optical, electrical and photocatalytic properties of anatase TiO(2) films with different preferred orientations, (101) and (004), this study clarified the relationship between the formation of metallic nanowires by thermally assisted photoreduction process and surface atomic bonding conditions of TiO(2). Experimental results show that the (101) anatase films which yielded much more Ag nanowires than the (004) oriented films and exhibited more complex superficial atomic bonding, which could be demonstrated by the Gaussian bands in photoluminescence spectra. This might lead to higher carrier concentration and mobility, as well as longer life time for photo-exited electrons and consequently a greater photocatalytic activity for reducing metallic ions.

Novel fabrication of Janus particles from the surfaces of electrospun polymer fibers.

A novel synthetic approach for the efficient fabrication of Janus silica particles was demonstrated by embedment of zero-dimensional colloids on one-dimensional polymer fiber surfaces, followed by the surface modification on the exposed silica hemispheres. Electrospinning of poly(methyl methacrylate) and poly(4-vinyl pyridine) blends produced polymer fibers with high specific surface area and desired surface hydrophilicities. Fiber compositions determined the colloid adsorption density and uniformity.